Dial for telephone service



F. M CLARENCE DIAL FOR TELEPHONE SERVICE Aug. 4, 1925.

Filed Feb. 12. 5

Patented Aug. 4, 1925.

UNITED STATES FRANCIS MGCLARENCE, OF HARROW, ENGLAND.

DIAL ron TELEPHONE SERVICE.

Application filed February 12, 1923. Serial No. 618,625.

To all whom it may concern:

Be it known that 1, Flowers MCCLARENCE', a subject of the King of Great Britain and Ireland, residing at Harrow, in the county of Middlesex, England, have invented certain new and useful Improvements in and Relating to Dials for Telephone Service, of which the following is a specification.

This invention relates to what are known as impulse dials for use in telephone services and particularly to those adapted to automatic telephones, inscribed with numerals, letters or other indications so ar-' ranged as to enable the combination of said numerals or indications to be made as will constitute the call of the required subscriber.

It frequently occurs in practice, however, that it is required to use such dials with mixed automatic and manual systems, and an object of the present invention is to permit such use in a simple and inexpensive manner with a single dial.-

It also occurs in practice that it is required to restrict the use of the dial or a. portion or portions, thereof until certain preliminary conditions are fulfilled by the caller, such as the prepayment of the amount 'of the call in a coincollecting box.

To'these ends the external appearance or construction of the dial, the arrangement of the numerals or indications thereon, and general mechanical features are or may be unchanged or may be of any convenient form, but the contact system and circuits are varied for the particular objects in view.

Accordingt'o the invention, in the use of the dial when requiring prepayment to enable a calling subscriber tobe placed in communication with a called subscriber or in the case of a subscribers meter requiring the registration of the call by mechanical means such as pressing a button, or electrically by means of a current from the exchange, functioning a relay; the usual impulse contacts are normally short circuited or restricted in some way, or'the dial is not introduced' int-o the circuit until. "such :pay-

' ments or operations are efiected, as by the necessary-coin or coins, press button or electrical current closing or opening contacts 1 which will remove the restrictions, the usual range of indications or so many of them as may be determined being available for such calls.

However, should it be desired to allow ah signal to pass over the line without prepay ment, for example when it is desired to call the exchange for a manual or non automatic communication 'or to give an alarm for fire, police or other call of an emergency character, then certain of the existing contacts are used or another one or other additional ones are provided which are not normally short circuited or restricted but are always operative and require no payment to be made for their function, these indications being preferably at the beginning or end of the main range of idications so as not to interfere, with the generalworking. Such further or additional contacts may be opened or closed to remove the restriction as by an auxiliary cam or contact device on the dial when moved to calling position, and on resetting of the dial be restored to their normal position, also by said cam being caused to close or reopen the contacts.

From the above description it will be seen that the invention in its broadest func: tional aspect consists in unblocking or normally retaining free for immediate operation a. contact or contacts relating to one ormore predetermined dial numerals or in-v I dications so that's'aid contact or contacts 1s or arenotdependent on the fulfillment of any preliminary condition or manipulation on the part of the user (beyond the ordinary operation of the dial) for such operation. 1 c f Thus the operation of calling a number for automatic may be the same as at present with prepayment or some other preliminary manipulation to free the required contacts, but the additional facility is provided of being able to immediately ring a manual or give an emergency signal when desired by moving the dial to another selected contact or other contacts without prepaymentor other preliminary condition.

An. embodiment of the invention is represented in the accompanying drawings in which :Fig. 1 is a front face view of the dial. Fig.2 is a rear elevation of the dial with the casing removed and showing the majority of the working parts and the mechanism' of the present invention applied thereto; Fig- 3 is an endelevation from the left of Fig.2. Fig. L is a detail view of a part hereinafter described and Fig. 5 is a simple circuit diagram showing thev application ofthe invention to oneoperative system.

v The general features of the impulse dial Y' may be replaced by CTI illustrated in the drawings are of a known or conventional kind and comprise two plates a and Z) the outer one a which con stitutes the dial proper being rotatable and provided with finger holes (71. to expose the numerical indications l to 9 and 0 inscribed on the face of the fixed inner plate Z). The diala revolves with spindle a mounted in the number plate 6. There is also provided on the latter a stop or abutment o to limit the rotation of the outer plate a this abut ment extending to the front of the dial. Between the dial a and number plate 6 is a drum (Z provided on its outer edge with ratchet teeth (Z engaged by a spring (Z on the dial, and further provided with peripheral teeth which mesh with the teeth of a pinion c which extends to the rear of the number plate. At the back of the latter there is coiled about the spindle a a spring f by which the dial is returned to normal after rotation and release. On the spindle e of the pinion 0 before mentioned is mounted a cam g of insulating material such as fibre the enlarged portions of which alternatively engage between a pair of spring c011- tacts h as the dial returns to normal position and thus transmits the required number of impulses to automatic selecting mechanism at the exchange according to the distance through which the dial has been rotated. The said spring contacts it are carried by a block b and suitably insulated at 72/ being extended by conductive strips it to terminals 7% connected to any suitable circuits. On the pinion spindle e is a toothed wheel 6 which engages a worm 6 on the spindle c of a centrifugal governor housed in a casing e and the springs of which are shown at e.

As aforesaid all the above mechanism is substantially known and is adaptable for use in the usual manner for automatic operation when the dial is moved from normal position from any of the indications l to 9 to transmit impulses over the line according to the subscribers number called.

To now turn to the improvement of the present invention a further cam is loosely mounted on the dial spindle a so that when the dial is rotated in the forward direction the end P of the spring f (which however a pin or other part) and which is passed through the spindle engages one side of said cam and drives it forward. Two additional spring contacts are provided also mounted in the block b with suitable interposed insulation k and connected by conductive strips 7: to other terminals k for circuit connections. The construction is such that in the ordinary operation of the dial between the indications 1 to 9 the cam j will not be rotated sufficiently far to engage between the contacts 70 but this will occur only when the dial is rotated for its full extent from indication 0 the spring end F then forcing the cam between the contacts and breaking the circuit until the tenth impulse or until the dial has completed its return movement whereupon spring end 7' acts on the other side of the cam and moves it from between the contacts to again close the circuit.

As an example of a simple dual arrangement with the present invention reference is directed tothe diagram of Fig. 5. Here the two cams g and are shown the former between the spring contacts h and the latter removed from contacts It these contacts being disposed in a circuit Z which includes in series other contacts m contained, for example, in a prepayment coin collecting box m and at which the money is held in suspense for an ordinary automatic call. When the contacts j and m are closed as shown the main lines X to the exchange are short circuited. When payment is made by a coin, separating contacts m the short circuit is removed and a prepaid automatic call can be made as usual. Again when the contacts L are separated by the auxiliary cam j the short circuit is also removed and a direct call can be made to the exchange without prepayment for the purpose above specified.

From the above description it will be seen that the following operations may be made and advantages obtained.

In automatic telephone areas where coin collecting boxes of the prepayment type are used, the impulse dial is normally short circuited, and is released for service by placing coins or tokens, in the box. For calls to a manual exchange in the case of trunk, junctions, telegrams, fire, police and service calls,

the manual operator, after taking particulars of the call, and sometimes before, refunds the fee to the caller.

By means of the improvements described above, the caller is enabled to dial the manual exchange without previously depositing a fee.

The two additional contacts added to the impulse dial are connected in series with the dial short circuiting arrangement of the coin collecting box. To dial a local number the caller places coins or tokens in the coin collecting box in the usual way. If the call is to the manual exchange the caller operates the dial and dials 0 (or other prearranged number or numbers) and the auxiliary cam 7' forced between its two contacts 70, this operation breaks the dial short circuit and at the end of the tenth impulse restores it.

Many municipal authorities object to the prepayment coin collecting box for all calls contending that it is unreasonable to expect the public to have'available a coin in the case of fire, police and ambulance calls and other emergency calls. a r v Similarly in' the case of telephone call meters the impulse dial is inoperative until the caller performs some operationsuch as pressing a button or a lever to remove the obstruction from the meter, in such cases this operation is a preliminary to the meter registering the call. The improvements do not interfere with the metering of local calls as at present but allow the subscriber to obtain the attention of the manual operator for the extra services mentioned without registering a local call, these extra services being ticketed by the operator and an account rendered periodically.

WVhat I claim as my invention and desire to secure by Letters Patent of the United States is 1. In a rotary impulse dial for telephone services having dial indications, contact devices cooperating with same for transmitting impulses over a line, and means for normally restricting the use of said contact devices, the combination of an additional dial indication and co-operating contact devices, and means operated by the rotation of the dial from said latter indication whereby the restriction on the first mentioned contact devices is removed to permit a direct co-m-- munication to be made over the line.

2. In a rotary impulsedial for telephone services, having dial indications, contact devices co-operating with same for transmitting impulses over a line for automatic communications and means for normally short circuiting said contact devices, the combination of an additional dial indication and co operating contact devices, and means operated by the rotation of the dial from said latter indication whereby the short circuit on the first mentioned contact devices is removed to permit a direct communication to be made over the line.

3. In a rotary impulse dial for telephone services having dial indications with a switch device embodying contacts co-operating therewith for transmitting impulses over the line on dialing from certain of said indications, and means for normally restricting the use of said switch device, the combination of an auxiliary switch device and contacts co-opera-ting therewith adapted to co-operate with other of said indications only when rotating the dial from said other contact, and means operated by said auxiliary switch device for removing the restriction from said first mentioned switch device to permit impulses to be directly transmitted over the line. 7

4. In 'a rotary impulse dial for telephone services having dial indications, contact devices cooperating therewith for transmitting impulses over the line, and means for restricting the use of said contact devices normally requiring a preliminary condition to be fulfilled by the caller for transmitting said impulses, the combination of an additional dial indication and additional contact devices co-operating therewith, and means operated by the rotation of the dial from said latter'indicatio-n for permitting impulses to be directly transmitted over the line without fulfillment of said preliminary condition. e

5. In an impulse dial for telephone services the combination of a rotary dial plate, dial indications thereon, a switch device embodying contacts, means for normally short circuiting said contacts, said short' circuit being removed by a preliminary operation on the part of the user for transmitting imulses over the line, in combination with an additional dial indication, a second switch device embodying other contacts cooperating therewith whereby on rotating the from .said additional. indication, the said short circuit may be removed to transmit impulses directly over the line irrespective of said preliminary operation by the user.

In witnesswhereof I have signed this specification.

FRANCIS McCLARENCE'. I

dial plate 

